The nuclear RPL4 gene encodes a chloroplast protein that co-purifies with the T7-like transcription complex as well as plastid ribosomes.
We have cloned and sequenced the cDNA and the gene coding for plastid ribosomal protein L4 (RPL4) from two higher plant species, spinach and Arabidopsis thaliana. Ribosomal protein L4 is one of the ribosomal proteins for which extraribosomal functions in transcriptional regulation has been demonstrated in prokaryotes. Sequence comparison of the two plant cDNAs and genes shows that the RPL4 gene has acquired a remarkable 3' extension during evolutionary transfer to the nuclear genome. This extension harbors an intron and codes for a glutamic and aspartic acid-rich amino acid sequence that resembles highly acidic C-terminal tails of some transcription factors. Co-purification of ribosomal protein L4 with plastid RNA polymerase and transcription factor CDF2 using different purification protocols as well as the surprising amino acid sequence of the L4 protein make it a likely candidate to play a role in plastid transcriptional regulation.
Trifa
Y
Y
Laboratoire de Génétique Moléculaire des Plantes, Université Joseph Fourier and Centre National de la Recherche Scientifique, B. P. 53, F-38041 Grenoble, France.
Privat
I
I
Gagnon
J
J
Baeza
L
L
Lerbs-Mache
S
S
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D002736:Chloroplasts / Q000737:chemistry*; D003001:Cloning, Molecular; D012321:DNA-Directed RNA Polymerases / Q000302:isolation & purification; D019143:Evolution, Molecular; D018628:Gene Dosage; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry; D018087:Plastids / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D018724:Spinacia oleracea / Q000737:chemistry; D014157:Transcription Factors / Q000302:isolation & purification; D014158:Transcription, Genetic / Q000502:physiology
D010940:Plant Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D014157:Transcription Factors; C056368:ribosomal protein L4; D012321:DNA-Directed RNA Polymerases